FALCOR4

Thank you for sharing this!!! A great piece of history and very sophisticated for it's time.. Now I wonder, who was it

Would love to see the articles.

I really like your idea of escaping! That's a good scheme. One of the other reasons for taking the longer path of splitting the data and adding a bias to it, frankly, was to make it more confusing to decode if someone did use a track reader. The thinking at the time.

Arrrr, I'm going to try this one more time. I keep losing my posts. We built routines that converted a word of data to two words of ASCII; this got around the problem with writing >F5 - >FF to the controller during track writes. That's probably what we did with the DiskAssembler but until I get all of my hardware back together I won't be able to recreate some of the things we were doing. Working on it. Attached are two subs; the first is from some disk production routines that convert a byte into two chars, the second is from one of the loaders that restores two word of chars into a word of data. Hope that helps.HEX ASCII conversion examples for track writers.txt

Curious, to what circuit/device are you providing the 2.9v? I just want to make sure not to mislead you because what Osgeld and Stuart are saying as a caution are very true. For example, if you ground that node then your 470ohm resistor will have to dissipate .3 watts, that's a worst case scenario. It will be a toasty warm 1/4 watt resistor in that instance.

Ah, good point! I assumed that is was in place and drawing current.

Another check you have is the GramKracker schematic you're reproducing. It's has an "as your looking into the port" set of pin numbers.

Shift838, use the voltage drop across the 470ohm resistor for that calculation and the the node voltage at your takeoff node (2.9v) for the 15ohm resistor. So; (12-2.9)^2 / 470 = .18 watts. (2.9)^2 / 150 = .06 watts. If I did my math correctly. Hope this helps.

Hi Jon, my honey do list was long this weekend so in the interest of self preservation I've been working it down. So, briefly, I believe that what you're interested in looking for is in the WDS1.DSKASM.BUILD directory. Especially look at the code titled MAIN. If everything is still in there it is part of what should build a DiskAssember disk from the DD1-DD5 files that should be in your FNL041186 directory. The main piece of information that got us tinkering with the disk formats was after I got a copy of the WD Storage Management Products handbook which has all the technical information for the WD177x, The Write Track function is a TYPE III command and from the book, "Data and gap information are provided by the computer interface" and "Normally whatever data pattern appears in the DATA REGISTER is written onto the disk with a normal clock pattern." The exceptions are patterns of >F5 or >FE which are interpreted as Data Address Marks with missing clocks or CRC generation. So, I just took that as I could write a continuous track with whatever data I wanted to put there and that's more or less what we did. As far as odd sectors, the controller allows 128, 256,512 and 1024 byte sectors so that's why you're seeing 1024 byte sectors as well, with some embellishments. Change of subject, I saw in an earlier post that someone was upset that they couldn't copy their legally obtained copies of MG products. I mentioned this in an email to you, Jon, but I'll repeat it here as well. Craig and I talked about this type of protection for a long time debating what the reaction might be. It was decided to go ahead with it in the hopes that it would fend off piracy for at least a year. This was Craig'l livelihood. It didn't take that long....and some were rightfully upset over it. In retrospect, we may (I say may) have actually accelerated the proliferation of tools like track readers and hardware that allowed easy access to memory. It definitely sparked interest in some as to how we were doing it. Sorry, I haven't been able to dig into this deeper for the moment. What I need to do is to duplicate my setup that I had back then to produce these products but I'm missing some hardware at the moment. Hope this helps

He was an inspiration and a pioneer for the 99.

Thank you for the post. I'm sorry to hear that, so many now have gone. He was someone who meant a lot to me. I'm not sure that the Gram Kracker would have ever happened if not for his inspiration.......

Trying to connect the history dots,do we know the status or where our esteemed colleague Heiner Martin might be today? He certainly was a leading pioneer for the TI99 community.

Thank you Sinphaltimus for taking on the restoration! The original was crusty old and water damaged.

Hi Matt, I caught this thread today; started at 2016 and just finished. I've been out of the game for over 30 years so I'm trying to get caught up with the help of a couple of good friends. Thank you for all the effort you've put into this project, it really opens up a tremendous number of possibilities. My imagination is already running wild, this is a powerful solution for expanding the old TI99! I'll keep checking in to see when you are at the distro point for your board. Keep up the great work.